Passivation layers, for example plasma oxide or plasma nitride layers, protect semiconductor dies against corrosion and mechanical damages. Typically a passivation layer is provided after patterning the topmost metallization or wiring layer. A stress relief layer, e.g., a polyimide layer, improves adhesion between the passivation layer and a molding mass encapsulating the semiconductor die. It is desirable to improve the reliability of semiconductor devices.